Compare the height of the old lever against the new. If the lever is too high or the gaskets/diaphragm is in the wrong order it will leak and lead to flooding.I don't have a gauge to check but lever is about .5mm (eyeball measure) below sides of carb when I place a strait edge over it.
Good morning JD - have just come in from the workshop. Done your tests:I'd start by putting pressure on the fuel inlet. Should be able to pump it up to at least 10psi before it "pops off".
If it doesn't hold pressure drop it in a jar of water & look for where the bubbles are coming from.
If it passes the pressure test you can test the nozzle check valve by pressing a straw or tube onto it & gently suck on/blow into it... Should only flow freely towards the venturi.
As previously stated, even if the nozzle check valve has an issue, there has to be something else amiss to cause over fueling
Just because you can't test it properly doesn't mean that it isn't a problem! Definition: The longest distance between two points is... A shortcut!Don't have anything I can control down to 10 psi so blew as hard as I could - no leak.
Okay - So a new needle valve should fix ???Just because you can't test it properly doesn't mean that it isn't a problem! Definition: The longest distance between two points is... A shortcut!
Forget the main nozzle for now. You have a needle and seat leak!
No new needle - carb kits (x 2) only came with gaskets and diaphragms.Not if it's the seat... Hasn't it got a new needle in it already?
You need to test it, or take it to someone who can
Make sure your nib on the metering diaphragm is the same thickness as the old one, if is thicker this will cause major flooding.
JD - carb cleaner was applied after strip and no rubber on needle valve.What did you use as a cleaner when you cleaned the carb out? Some aggressive cleaners/solvents will damage the soft components like needle points, valves, diaphragms etc. That in combination with compressed air would explain a lot
Sounds promising.Gentlemen - My son (a bit of 2/aficionado) may have found the problem - there appears to be a "Welsh" plug missing from the diaphragm side (probably blown off by me). It would be in the shape of a round cornered triangle. The plug covers three small holes that would have been letting unmetered fuel into the carb throat.
My son has already started making a replacement out of aluminium sheet. He is unlikely to be able to fashion an interference/press fit, as per original, so will use aviation gasket goo to secure it in place.
Fingers crossed, the flooding issue will have been fixed.
The full carb kit might have the plug. Methacrylate/crazy glue hold up to fuels pretty good.Sounds promising.
There are very few sealants that will hold up inside a carburetor. I would fashion a new welch plug out of the base of an aluminum can so that it has a bit of a dome that you can flatten into place like a regular welch plug.
Good luck, keep us posted
From $tihl/$teal will be expen$ive. From 034 IPL (pgs 38-39) their carb kit 1128 007 1065 , lists parts 3-10, does not list #14 the plug. That's curious?
Watch out. Zama used two different shapes of welch plugs in the C3 carb (assuming that is the one that you have). As far as making a welch plug fuggetaboutit! BOTH Walbro and Zama can't get the plugs to seal reliably using precision parts and factory tooling. They use a proprietary secondary sealant. Once you get the correct plug installed run a THIN bead water THIN of super glue around the edge of the plug. Put the carb on a shelf for 48 hours to make sure that the super glue cures completely. Be sure to clean the new plug and the recess in the carb with brake cleaner before installing.